Valve for power-driven tools.



No. 630,447. `Paten'ted Aug. 8, |899.

- F. H. CATHCART.

VALVE FOR'POWEB DRIVEN TOOLS.

(Application led Mar. 16, 1897.) (No Model.) 2 Sheets-Sheet I.

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` muawtofc.' WVM/Loa am No. 630,447. Ptented Aug. s, |899.

F. H. CATHCABT. VALVE FOR POWER DRIVEN TOOLS.

(Application led Mar. 18. 1897.) (No Model.) 2 sheets-sheet 2'.

UNITEDV ,STATES PATENT rrrcn.

FRANK II. OATIIOART, OF ALEXANDRIA, VIRGINIA, ASSIGNOR TO 'll-IE EMPIRE ENGINE AND MOTOR COMPANY, OF NEIV YORK, N. Y.

VALVE FOR POWER-DRIVEN TooLs.

SPECIFICATION forming part of Letters Patent No. 630,447, dated August 8, 1899.

Application iiled March 16, 1897. Serial No. 627,853. (No model.) l

-To all whom, it may concern:

Beit known that I, FRANK H. CATHCART, of Alexandria, in the county of Alexandria, State of Virginia, have invented certain new and useful Improvements in Valves for Power- Driven Tools, of which the followingis a complete speeiiication, reference being had to the accompanying drawings.

The object of my invention is to produce a Io reversible power-driven tool of the type `shown,for example, in my Patent No. 494,461, dated March 28, 1893, adapted to be operated by compressed air or other fluid, and I accomplish that result by the specific means of improved valve mechanism.

I'Ieretofore, although a demand has existed for a reversible pneumatic drill, and notwithstanding the entire practicability of producing a reversible rotary engine in large zo sizes, yet, owing to the fact that in atool of the class to which my present invention belongs any considerable increase in weight is objectionable, a reversible pneumatic drill or -similar power-driven tool hasnot been pro- 2 5 duced. l

In the'accompanying drawings, Figure I is a top plan View of my tool. Fig. II is a section of the same, taken transversely to the axis of the piston. Fig. III is a section taken at 3o right angles to the view shown in- Fig. II and illustrating the addition of a breast-plate. Fig. IV is a view similar to Fig. Il, showing a different form of handle.

Referring to the figures on the drawings, 1 indicates the cylinder or case, 2 the cylinderheads, 3 the piston, 4 the piston-blades, and` 5 the piston-shaft, of a rotary engine of suitable typefor example, of the type shown in my Patent No. 495,303, dated April 11, 1893.

6 indicates the stem that forms an axis for the tool-shank, and 7 the hollow body or bowl, provided with a rim 8, to which is secured a gear 9, intermeshing with gears or pinions 10 upon the opposite ends of the shaft 5, all subi stantially as described in my Patent No.

In Fig. IV a single handle 12, `extending coaxially with the stem 6` upon the opposite .side of the cylinder 1, is illustrated.

In Fig. III a tubular supporting-piece 13, corresponding in location to the handle 12 in Fig. IV, is illustrated, provided with a breastpiece 14, by means whereof the drill may be used as a breast-drill in the usual manner.

My present invention consists in providing means for practically reversing the operation of the shaft 5 whenever required, and I accomplish that object by the employment of a reversing-valve, immediately hereinafter described.

15 indicates the valve-chamber in each` of the gures, which is preferably provided at its opposite ends With iittings 16 and 17, which serveto limit the reciprocal movement of `a sliding valve *18.V The valve-chamber 15 and valve 18 within the same are located transversely to the axis of the piston 3, as illustrated. The fitting 17 terminates in its outer 'end in a vstuffing-box 19, within which works a valve-stem 20, that is secured` at oneend,

termediate stud 23, as shown in Fig. IV.

The rock-bar may itself constitute a handle,

as illustrated in Fig. IV, or it may be provided with one or more extensions 24, that act as handles. If more than one extension 24 be employed, as illustrated in Fig. II, one may be located upon one side of the tool-handle and the other upon the other side thereof. The operation of the rock-bar is adapted, through the valve-stem 20, to produce reciprocal movement of the valve 18 within its chamber 15. The valve-chamber is provided upon one side with a threaded connection 25 for the insertion of a duid-supply pipe, and the bore of the connection communicates with an interior annular recess 26, formed in the interior wall of the chamber 15. The valve 18 is provided with a corresponding recess 27, formed in its exterior wall.

The recesses 26 and 27 when united constitute a fiattened or elongated annular recess in the opposing walls of the chamber 15 and IOO valve 18, respectively. Through those recesses, by means of the reciprocation of the valve within its chamber, communication between the supply-pipe connection and the passages 28 and 29, respectively, of the cylinder may be made and broken, the valve being provided at its opposite ends with annular walls 30 and 31, respectively, that work across the mouths of the passages 28 and 29, respectively, as illustrated in Figs. II and IV.

The interiorof the valve 18 is provided with an open chamber 32, which communicates with the interior of the `valve-chamber th ro ugh openings 33 in the opposite ends of the valve. The openings may be defined by skeleton heads 34 in the opposite ends of the valve,

which serve to define the central chamber 32 and afford means of connection between the valve and the valve-stem 20.

Through the presence'of the interior annular recess 26 in the valve-chamber and the eX- terior annular recess 27 in the valve the valve is steam or fluid balanced upon all sides. It may be supported at its opposite ends with springs 35 and 36, respectively,which, resting at one end, respectively, against the fittings 16 and 17 and at the other against the end of the valve,serve to yieldingly conii ne the valve in the inoperative position illustrated in Fig. II.

The operation of my invention is as follows: Suppose that the mechanism is in the position shown in Fig. Il, for example. In such position steam or other fluid entering through the connection 25 is confined Within the re- A the passage 29 to the hollow chamber 32 within the valve.v

The apparatus which I have devised and herein described constitutes a practicable rotary motor adapted for the driving of drills and like tools and provided with a reversingvalve device. As stated hereinbefore, I am aware that it is not new, broadly considered, to construct a rotary engine with a reversingvalve; but so far as I am aware that has heretofore been practicable only in large engines, where the matter of size and weight is not relatively important. In the device which embodies my present invention several features enter into the construction of the engine which make it possible to introduce a reversing mechanism without materially increasing either the size or the weight of the engine. 'Ihe following-named features contribute to this result: The passages 28 and' 29, which communicate between the fluidsupply pipe and theinte'rior of the cylinder on opposite sides ofthe piston, converge within the Walls of the cylinder toward 'their outer ends, so that where they communicate with the supply pipe or chamberthey are close together, and a single short valve may be employed to-control the openings toboth passages. Again, the exhaust-passage is situated in line with the valve, whereby a very shortmovement of the-valve will suffice to cover and to uncover-'both the supply and the exhaust passages. Another feature of construction of importance is the hollow valve, and especially is this feature of great advantage when it is combined with the exhaust-passage arranged as just set forth.

What I claim is*- 'Ihecombination of the cylinder, the piston therein, a fluid-supply pipe and the passages leading therefrom to the interior of the cylinder on opposite sides of the piston, a sliding reversing-valve adapted to control the openings to the said passages, and the springs which bear upon the said valve and normally hold it in a position to cover the openings of both of the said passages, substantially as set forth.

. In testimony of all which I have hereunto subscribed my name.

FRANK H. CATHCART.

Witnesses:

J. DU PRATT WHITE, JOHN M. HITE. 

